I have replaced 3 disc brake calipers on my 2001 pt cruiser. after bleeding all 4 brakes 3 times, I started the car and brake pedal goes to floor. is my brake booster shot?

Are you loosing brake fluid after you tighten that bleeder screw back? Your brake booster helps aid in the vacuum of the car - if you have an internal issue with that brake booster - you should check any vacuum lines coming off that booster. If you can answer with your year, make and model I can get you a more in depth answer - there are other things that can be causing your issues as well - from the master cylinder to other things. Good Luck. There's also a way to test that brake booster - do you have a pressure/vacuum gauge?

The piston seals could be bad, and bleed the brakes to make sure.

Start the engine, fill up full the brake fluid reservoir, and let someone press the brake pedal down to the floor for 3 times,, bleed the bleeder screw behind the tire.. position yourself closed to back plate of drum or caliper for easy bleeding work. when the bleeding screws is loosed brake fluid leaks with a bubbles. then close it again and tell the guy in the pedal brake to press it again until a hard press is felt and bleed the bleeder screw again, stop only the process when there is a hard pressing already on the brake pedal which is the brake system is now working properly.

1. Check the fluid level in the reservoir after bleeding each wheel. Add DOT3 fluid, if necessary.
2. If the master cylinder was disassembled or if the reservoir becomes empty, bleed the air from the master cylinder as follows:
   1. Disconnect the brake lines from the master cylinder.
   2. Slowly depress the brake pedal and hold it.
   3. Block off the outlet plug with your finger, and release the brake pedal.
   4. Repeat 3 or 4 times.
   
   
3. Bleed the brake starting with the one furthest from the reservoir and then the next furthest, etc.
   
4. Depress the brake pedal several times, then loosen the bleeder plug with the pedal held down.
5. At the point when fluid stops coming out, tighten the bleeder plug to 11 Nm (8 ft. lbs.), then release the brake pedal.
6. Repeat until all the air in the fluid has been bled out.
7. Repeat the procedure to bleed the air out of brake line for each wheel.
8. Check the fluid level and add DOT3 fluid if necessary.

For left hand drive vehicles: (If the car does not have ABS system you do not need any diagnostic equipment!)

IMPORTANT NOTE: You need using diagnostic equipment connected to the data link connector of the car in order to bleed the ABS block. Follow instructions by scantool equipment for bleeding the ABS block.

1. This bleeding procedure requires two people. Remove the brake system reservoir cap, and fill up with new brake fluid until "MAX" level is reached.
2. Lift the car, or use a channel for access under vehicle.
3. Put the gearbox in "N" - Neutral position, or in "P" - Parking position for automatic transmission.
4. Start the engine and push the brake pedal firmly for 4 - 5 times to the floor, and maintain the brake pedal pushed to the floor.
5. Begin with the rear right wheel. Another person remove the dust cap and loose the brake caliper bleeding screw until the brake pedal goes to the floor. At this moment maintain the brake pedal pushed to the floor, engine idling, and tight the brake caliper bleeding screw. Use a plastic hose: one end connected to the brake caliper bleeding screw, and another end inside a recovery bottle for used brake fluid.
6. Repeat steps no.#4 and no.#5 until no air flows through the brake caliper bleeding screw. Tight the brake caliper bleeding screw, and put the dust cap in their place.

IMPORTANT NOTE: All the time check the brake fluid level in the brake system reservoir, and fill up if necessary!

7. Push the brake pedal firmly for 4 - 5 times to the floor, and maintain the brake pedal pushed to the floor, engine idling.
8. Continue with the rear left wheel. Another person remove the dust cap and loose the brake caliper bleeding screw until the brake pedal goes to the floor. At this moment maintain the brake pedal pushed to the floor, engine idling, and tight the brake caliper bleeding screw. Use a plastic hose: one end connected to the brake caliper bleeding screw, and another end inside a recovery bottle for used brake fluid.
9. Repeat steps no.#7 and no.#8 until no air flows through the brake caliper bleeding screw. Tight the brake caliper bleeding screw, and put the dust cap in their place.

IMPORTANT NOTE: All the time check the brake fluid level in the brake system reservoir, and fill up if necessary!

10. Push the brake pedal firmly for 4 - 5 times to the floor, and maintain the brake pedal pushed to the floor, engine idling.
11. Continue with the front right wheel. Another person remove the dust cap and loose the brake caliper bleeding screw until the brake pedal goes to the floor. At this moment maintain the brake pedal pushed to the floor, engine idling, and tight the brake caliper bleeding screw. Use a plastic hose: one end connected to the brake caliper bleeding screw, and another end inside a recovery bottle for used brake fluid.
12. Repeat steps no.#10 and no.#11 until no air flows through the brake caliper bleeding screw. Tight the brake caliper bleeding screw, and put the dust cap in their place.

IMPORTANT NOTE: All the time check the brake fluid level in the brake system reservoir, and fill up if necessary!

13. Push the brake pedal firmly for 4 - 5 times to the floor, and maintain the brake pedal pushed to the floor, engine idling.
14. Continue with the front left wheel. Another person remove the dust cap and loose the brake caliper bleeding screw until the brake pedal goes to the floor. At this moment maintain the brake pedal pushed to the floor, engine idling, and tight the brake caliper bleeding screw. Use a plastic hose: one end connected to the brake caliper bleeding screw, and another end inside a recovery bottle for used brake fluid.
15. Repeat steps no.#13 and no.#14 until no air flows through the brake caliper bleeding screw. Tight the brake caliper bleeding screw, and put the dust cap in their place.
16. Now the brakes are bleeded. Check the brake fluid level in the reservoir. Fill up with new brake fluid until "MAX" level is reached. Put back the brake reservoir cap.
17. Test the car brake system. The brake pedal movement no more than 1/3 of total stroke until the floor, when brake pedal is applied. Maximum admissible is 1/2 of total stroke.

More than likely it is not your calipers. Sounds like you have got an air pocket in the brake system. You need to get a helper and bleed all four of your brake lines at the wheel. Have someone pump up the brake 3-4 times and hold the pedal and then release the pressure of the brake line at the caliper. Should be a 8 mm wrench (maybe 10 mm). Do that 3 times at each wheel and you should have your brake pedal back to normal. If that doesn't fix it, you need to look at the master cylinder because that will probably be the problem. Let me know if you have any questions. Thanks for using FixYa!

It sounds like you have a bad mastercylinder cause when you panic brake it doesn't have time to bleed through the valve in the cylinder but under normal braking your foot is on pedal longer in turn giving the fluid time to bypass the valve in the mastercylinder in turn the pedal going to the floor.

If the pedal goes to the floor you may still have air in the system.I assume that the pedal was ok before you started and that you may have opened one or more of the bleed screws.
Check the fluid level at the master cylinder.It need to be at the proper level.
You will need to be positive that no air is in the system.If you are not familiar with brake bleeding do not attempt as you may cause more problems.
The use of a clear plastic hose that fits snugly over the bleed screws at the calipers and is immersed into a clear container may be helpfull to see if any air bubbles are present in the fluid.
A bleed kit may be obtained from an automotive supply store.

For front brake pads replacement you need only usually wrench set, inclusive 7 mm allen key also. But for rear brake pads replacement you need obligatory a special caliper piston pressing tool, in order to press back rear caliper piston with parking brake automatic adjustment!!! For front brake pads. First you must verify yours front brake disc diameter: 280 mm or 288 mm. (On my car y have 288 mm). After that you can buy the brake pads (with wear sensor). For change front brake pads you must raise vehicle, remove wheels, extract the retaining spring of the caliper, and remove the caliper as follow: 1. Do not disconnect the brake hose from the caliper, and do not allow the caliper to hang by the brake hose! 2. Remove top and bottom caps (on back side of the caliper) for access to guide pins, then unbolt and remove them from the brake carrier. Remove the caliper. 3. Now you must thoroughly clean the brake calipers (free of grease). 4. Remove outer brake pad from brake carrier. 5. Pull inner brake pad out of brake caliper piston. 6. Check up the brake fluid level on the reservor, and emptying if neccessary! 7. Push piston back into brake caliper housing. 8. Install inner brake pad (with expanding spring) in brake caliper piston. (Arrow marked on pad - if exist, must point in direction of brake disc rotation when vehicle is moving forward). 9. Install outer brake pad into brake carrier. 10. Bolt brake caliper housing to brake carrier using two guide pins. Tightening torque is 25 Nm. 11. Install both caps. 12. Insert retaining spring into brake caliper housing. Important: Depress the brake pedal firmly several times while the car is stationary so that the brake pads adjust to their normal operating positions!!! Check brake fluid level and top up if neccessary!!!

Valve is chk valve for vacuum. Any recent brake work? May just need brakes replaced.